Gut health has become a very popular topic. Most people understand how much gut health can affect their overall well being. What many don’t realize yet is how fasting can help improve gut health fast. Fasting is free, it’s flexible, and it can completely change your life.
The Importance of Your Gut Microbes
Did you know that the cells in your gut outnumber your own cells 10 to 1? In a way, you are mostly microbes. Consequently, you cannot overestimate the importance of your microbiome.
Your Microbiome and Your Health
The bacteria in your gut help digest food, regulate your hormones, your immune system, and even produce vitamins! They protect against other bacteria that cause diseases. Your microbiome can have an impact on the following health conditions:
- Autoimmune diseases: It appears that autoimmune diseases are passed in families not through their DNAs but through the family’s microbiome. Autoimmune diseases such as diabetes, rheumatoid arthritis, muscular dystrophy, multiple sclerosis, and fibromyalgia are associated with dysfunction in the microbiome.
- Obesity: Gut microbes are different between obese and lean twins. These microbes affect hunger and satiety signals.
- Hypertension: We observe an increased Firmicutes/Bacteroidetes ratio and a significantly reduced richness in the microbiome diversity in hypertensive patients.
- Cardiovascular disease: The gut microbiome may affect arterial wall properties.
- Depression: A combination of probiotic species Lactobacillus helveticus and B. longum can reduce depression scores in patients diagnosed with major depressive disorder (MDD).
- Cancer: We estimate that the gut microbiome accounts for 20% of all cases of cancer worldwide. We associate specific cancer with increases in specific bacteria. For example, prostate cancer patients have more Bacteroides massiliensis.
- Inflammatory bowel disease: Changing the gut microbe composition can improve the severity of inflammatory bowel disease symptoms.
- Longevity: Akkermansia and Christensenellaceae are bacteria that promote longevity.
The extent to which your gut microbiome affects your health is such that is has been called an “essential organ” of the human body. To learn more about the importance of gut health, read 5 Ways You Can Restore Your Gut Health Naturally and Why It Matters.
What Is a Healthy Gut?
The microbiome differs significantly not only between healthy and sick individuals but it also differs among healthy people. However, there are some general factors that may help define a healthy gut.
Microbe Diversity
The human gut harbors trillions of bacteria. More diversity is associated with improved health. A study found that long-living individuals had a greater microbiome diversity. Furthermore, urbanization is associated with a loss of microbial organisms and genes. Our Western diet causes a loss of microbial diversity including organisms able to ferment fiber-rich foods.
Microbial Balance
A healthy gut microbiome includes a balance of good bacteria and pathogens. Specific members of a bacterial community can play an important functional role in the fight against viruses and pathogens.
Microbe Functions
What your gut microbes do with the food you ingest matters just as much as what you eat. For some people, eating a piece of banana will have the same glycemic impact as eating a piece of double-fudge triple chocolate banana bread with nuts. It turns out that certain microbes contribute to how your body responds to carbs. In a healthy gut, the production of antimicrobial signals and different short-chain fatty acids such as butyrate and propionate helps improve glucose metabolism and immune function.
Mucus Layer Thickness
A thicker mucus layer is associated with a better composition of the microbiome. The mucus layer impacts the composition of the microbiome and vice versa.
The Effects of Fasting on Your Microbiome
Humans are not meant to have constant access to food. Fasting provides the body with the opportunity to regenerate as a whole. I was impressed to learn that biweekly 24-hour fasts increased the lifespan of rodents by up to 30%. Furthermore, as you could expect, fasting has benefits specifically related to the gut microbiome.
Your Microbiome Has a Circadian Rythm
Your circadian rhythm regulates your metabolism. A stable and balanced circadian rhythm helps support your mood, your digestion, your heart function, and immunity. Did you know your gut bacteria have a circadian rhythm? Cues like light, temperature, and feeding signal your body what physiological processes need to happen. Twenty percent of your gut bacteria fluctuate during the day depending on what time it is. The following illustration shows the relationship between your circadian rhythm and your microbiome.
Effect of Fasting on Your Circadian Rythm
Fasting tells your microbiome when it’s time to detoxify and regenerate. You can even remediate circadian rhythm disruptions by following a pattern of timed feeding. Chronic disruption of your circadian clock is linked with a number of diseases, including obesity, diabetes, and cancer. Dietary interventions like fasting help remediate these disruptions. To accomplish this, you need to limit your hours of eating to 9-12 hours and make sure these hours are earlier in the day. It prevents weight gain and improves the diversity of your microbiome.
Intermittent Fasting Improves Your Gut Health
The impact of intermittent fasting on the gut microbiome is becoming more apparent. Going without calories for at least 12 hours on a regular basis seems to increase your microbiome diversity and your tolerance against the “bad” bacteria. Not only that, but it also improves the thickness of your intestinal mucus layer.
How Long Do You Need To Fast?
As I mentioned already, a 12 hour fast is enough to improve your circadian rhythm. However, are there benefits that require a longer fast? Apparently, many “bad” gut bacteria starve more quickly than the good bacteria, which is another reason why fasting may be beneficial to your gut health. However, it seems that if you practice intermittent fasting short term and return to your Standard American Diet, the benefits of fasting on your microbiome will not be sustained. To maintain the benefits, it is important to practice fasting regularly and adopt a healthy diet.
Prolonged Fasting and Your Gut Bacteria
Longer fasts (2 days or more) can restore the integrity of your intestinal walls. Furthermore, a study conducted across classes of animals found that an extended fast produced a greater variety of gut bacteria. Even just eating more fiber and plants for 10 days will significantly alter your microbiome. When you understand how fast you can heal your gut, there is no reason not to take action.
Fasting to Reset Your Digestive System
Have you ever heard the word autophagy? Autophagy is the body’s cell regeneration process. When you fast, your whole body is regenerating. Furthermore, your digestive system is healing. Fasting from anywhere between 24 and 96 hours has been shown to have a positive effect on reducing gut permeability (leaky gut) and digestive issues.
Heal your Digestive Issues
Digestive issues are caused by a combination of poor diet and leaky gut. Giving your digestive system a break trough fasting will alleviate most issues. Furthermore, you can use fasting effectively as a therapy to heal irritable bowel syndrome (IBS). In one study, the subjects fasted for 10 days while the control received normal medication treatment. The conventional treatment improved only 3 out of the 10 symptoms of the patients. Fasting, however, improved 7 out of the 10 symptoms. These symptoms were things like nausea, abdominal distension, abdominal pain-discomfort, diarrhea, etc. See the potential?
Fasting for Your Metabolism
Ok, we talked about the impact of fasting on your circadian rhythm, your microbiome, and your digestive system. Its benefits don’t end there. It will also cause changes in your microbiome that will benefit your metabolism.
Fat Burning Bacteria
Your body includes white and beige fat cells. White fat cells store calories while beige fat cells burn energy. Converting white fat into beige fat could help fight obesity. Well, guess what? Your microbiome can help do that! How? Through their fermentation products called lactate and acetate. Two recent studies show how intermittent fasting turns white fat cells into beige fat cells by helping your microbes produce lactate and acetate.
Fat Burners Vs. Sugar Burners
I am sure you have heard about ketosis by now. Ketosis is a state in which your body is no longer burning glucose for energy, it’s burning fat instead. Fasting for just 12 to 16 hours can help achieve ketosis. Fasting not only improves your gut health and your metabolism by helping your body get rid of white fat cells but by turning you into a fat burner.
Your Microbiome and Its Role in Obesity
Research indicates that your microbiome could also play a major role in whether or not you become obese. Your microbiome determines not how your body stores and utilizes energy. Studies on twins have demonstrated that transplanting the microorganisms from an obese twin into the lean twin caused the lean twin to become obese and vice versa. Moreover, we have found that antibiotic use and low microbiome diversity are associated with a higher risk of obesity.
Fasting for Longevity
It turns out that gut health and aging are closely related. The microbes in your gut play an important role in how well you age. Your growth hormone production decreases beginning in your early twenties. As your growth hormones decline, you will start feeling and looking older. Fortunately, there is a way to encourage your body to produce more growth hormones. It’s called fasting! One study showed that while fasting for twenty-four hours, human growth hormones increased an average of 1,300% in women and nearly 2,000% in men. Moreover, high-intensity workouts increase human growth hormone production.
Forms of Fasts for Your Gut Health
Fasting helps improves your gut health because it is a way to give your digestive system a break. However, keep in mind that you don’t need to go completely without food for an extended period of time. In fact, giving your digestive system a break AND the nutrition it needs may be a more effective cure. Here’s how you can get started with fasting (increase the benefits by making sure you consume 40% or less your normal caloric intake when you are ready for maximum benefits):
- Intermittent fasting: Read Intermittent Fasting for Women to learn more about the best way to practice intermittent fasting.
- Fasting mimicking: Read The Fasting Mimicking Diet: Benefit From Fasting Without Giving Up Food. Fasting mimicking is a prolonged fast that helps you reap the benefits of prolonged fasting without having to go completely without food.
- Eating a “mono” diet of one food (for example one fruit),
- Consuming bone broth on a fast.
- Eating only salads.
- Doing a juice or smoothie fast: Read about my favorite 3-Day Detox Diets.
- Eating only soups: The GAPS Diet Intro takes advantage of the healing power of soups and broths.
In Summary
What we eat, how much we eat, when we eat as well as when we DON’T eat impacts your gut bacteria. Even your macros such as the number of carbs, protein or fats cause relatively significant changes in your microbiome. You can use fasting as a powerful tool to improve your gut health. If you are a woman, make sure to read my article Intermittent Fasting for Women. As a woman, some specific hormonal reactions come into play. Understanding what they are will help you get the most out of your fasts.
